The present invention relates to an optical device for viewing scenes. The invention is particularly applicable for use in night vision goggles having means for intensifying the image and further means for injecting additional information into the viewed scene; the invention is therefore described with respect to this application.
Night vision goggles having image intensifier means, to enable viewing scenes by moonlight or starlight, are known. Also known are such night vision goggles having means for injecting additional information into the viewed scene, such as electronically generated information to be viewed simultaneously with the viewed scene without removing the goggles. An example of the latter type of device is illustrated in U.S. Pat. No. 4,000,419. That patent describes an arrangement wherein the additional information injecting means is located adjacent to the eyepiece of one of the monocular assemblies.